Summary: Hidetoshi Tokuda
CS740 Reading Assignment
2 / 15 / 2007
Summary of "MIRO: Multi-path Interdomain ROuting"
This paper proposes a bilateral negotiation based multi path inter-domain routing,
which enables ASes to choose multiple routes to one destination with out changing the whole
internet protocol or routers. The problem that the authors describe is that the existing inter
domain routing is completely relying on BGP. The characteristic of the BGP is path vector and
policy based which provides strict single route for each destination. Unfortunately, not all of
the routes are optimized from a perspective of performance. MIRO proposes an extension to
the current BGP so that ASes could require the AS on the path to provide an alternative route for
the destination by using tunneling technique which sounds similar to NAT or VLAN. This will
enable users to avoid un-trusted ASes on the path, load balancing by using multiple paths, and
increasing reliability by using as a backup.
The authors describes that one of the strengths of MIRO is that because it is based on
current BGP and backwards compatible, it is easy to deploy. But as it gets in details, it seems
like each ASes that has a tunnel will need to keep a soft state of it and therefore, the routers in
the AS will also need to carry some state. This violates the "Smart End Host & Dumb
Network" philosophy and I believe that it would be better to choose overlay network even if it
will cost a lot. Also, as authors mentions in the paper, MIRO has not solved the security